In postal sorting centers sorting machines are used comprising in general both a restricted number of stackers of large capacity assigned to the major destinations of the articles to be sorted and a greater number of receptacles, called pigeonholes, of smaller size, for the routes or destinations which are little-used.
It will be understood that the conveyors of sorting machines allocated to feeding articles to the pigeonholes corresponding to little-used destinations carry a flow of articles to be sorted much less than their capacity, at least in statistical terms. There is thus under-usage of these conveyors, which tends to increase the overall cost of operation of the sorting installation.